Insecticidal and miticidal compositions

ABSTRACT

This invention relates to an insecticidal and miticidal composition which contains as active ingredients chlorfenapyr [4-bromo-2-(chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile] in combination with asynergistic amount of at least one of a carbamate-type insecticidal compound.

This application is a 371 of PCT/JP97/04498, filed Dec. 8, 1997.

FIELD OF THE INVENTION

This invention relates to insecticidal and miticidal compositions whichcan be effectively applied in the agrohorticultural field. In moredetail, it relates to insecticidal and miticidal compositions whichcontain two or more active ingredients and are especially effectiveagainst pest and mites which have acquired resistance to commercialinsecticidal and miticidal agents.

BACKGROUND OF THE INVENTION

4-Bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile(hereinafter referred to as chlorfenapyr), which is an active ingredientof the insecticidal and miticidal composition of the invention, is knownto be effective against insects such as Hemiptera pests such asleafhoppers (Dolto cephalidae), Lepidoptera pests such as diamond backmoth (Plutella xylostella), common cutworm (Spodoptera litura) and appleleafminer (Phyllonorycter ringoniella) and Thysanoptera pests such asThrips palmi and yellow tea thrips (Spirtothrips dorsalis) andagrohorticultural pests such as mites such as two-spotted spider mite(Tetranychus urticae koch). Kanzawa spider mite (Tetranychus kanzawaikishida) and Aculops pelekassi [Japanese Laid-open (Kokai) PatentPublication No. 104042/89].

The second active ingredient of the insecticidal and miticidalcomposition of the invention includes at least one of the carbamate-typecompounds which are known to be effective insecticidal agents againstagricultural pests such as Hemiptera, Lepidoptera and Coleoptera insectsand mites.

Although insecticidal and miticidal agents have been developed in orderto control various pests such as agrohorticultural pests or hygienicpests and in practice have been used as a single or a mixed agent, pestswhich have acquired resistance against various agents have beenappearing as a result or the repeated use of these agents.

In particular, important economic pests in agrohorticulture such asspider mites (Tetranychidae), which have a propensity to easily developresistance against pesticidal agents due to their ability to depositlarge numbers of eggs and produce large numbers of generations which,themselves, require only a few days for development are of greatconcern. Resistance development in this pest family is also favored by ahigh mutation rate and frequent inbreeding, due to minimal migration.For these reasons, two-spotted spider mite (Tetranychus urticae koch),Kanzawa spider mite (Tetranychus kanzawai kishida), Aculops pelekassi,and the like have acquired resistance, to some degree, against almostall existing pesticidal agents. Therefore, in order to prevent andcontrol the damage caused by spider mites, development of a newinsecticidal and miticidal agent which shows a high effect againstspider mites which have acquired resistance against the conventionalmiticidal agents is highly desirable.

However, to obtain an insecticidal and miticidal composition which showsno cross-resistance with existing insecticidal and miticidal agents, hasno toxicity problems and has little negative impact on the environment,is extremely difficult. Therefore, a means to delay or prevent thedevelopment of resistant strains of pest species is always being sought.In order to apply an effective agent as long as possible, a rotationalapplication of agents with different mechanisms of action is adopted forgood pest management practice. However, this approach does notnecessarily give satisfactory pest control. Therefore, after aresistance problem has occurred, a countermeasure to resistance bycombining insecticidal and miticidal agents has been studied. However, ahigh synergistic action has not always been found.

Therefore, it is an object of this invention to provide an insecticidaland miticidal composition which demonstrates a high controlling effecteven against spider mites which have acquired resistance againstchlorfenapyr.

SUMMARY OF THE INVENTION

In order to establish a countermeasure to a resistance problem in spidermites against chlorfenapyr before such a problem occurs, the synergisticaction with the existing insecticidal, miticidal and fungicidal agentswas studied using resistant species which have been artificiallyestablished in the laboratory by selecting spider mites which have beentreated with chlorfenapyr. Thus, it has now been found that aninsecticidal and miticidal composition which contains as activeingredient chlorfenapyr in combination with at least one of thecarbamate-type insecticidal ingredients shows a joint action orsynergistic effect which could not be foreseen from each individualingredient alone.

DETAILED DESCRIPTION OF THE INVENTION

The insecticidal and miticidal composition of the invention isparticularly effective for the control of spider mites such astwo-spotted spider mite (Tetranychus urticae koch), Tetranychuscinnabarinus (Boisduval), Kanzawa spider mite (Tetranychus Kanzawaikishida), hawthorn spider mite (Tetranychus viennensis zacher), and thelike.

Advantageously, the insecticidal and miticidal composition of theinvention shows not only a synergistic miticidal effect against theabove-mentioned spider mites, but also demonstrates simultaneous controlof troublesome pests such as leafroller moths (Tortricidae),Carposinidae, leafminer moths (Lyonetiidae), plant bugs (Pentatomidae),aphids (Aphididae), leaf-hoppers (Deltociphalidae), thrips (Thripidae),diamond back moths (Plutella xylostella), Mamestra brassicae, leafbeetles (Chrysomelidae), whiteflies (Aleyrodidae) and the like onimportant agronomic crops such as fruit trees, for example citrus, appleand pear; tea plants; vegetables and the like.

Chlorfenapyr, which is an active ingredient of the insecticidal andmiticidal composition of the invention is a known compound described inJapanese Laid-open (Kokai) Patent Publication No. 104042/89 and its wayof using as agrohorticultural insecticidal and miticidal agent is shownin the Publication. It can also be easily synthesized according to themethod described in the Publication.

As carbamate-type insecticidal ingredients which are suitable for use asthe second active ingredient in the composition of the invention, manycompounds are known. For example, illustrative generic names andchemical names are listed hereinbelow. These examples, however, are notintended to limit the scope of the invention.

Generic name: Chemical name BPMC: 2-sec-Butylphenyl-N-methylcarbamateMIPC: 2-Isopropylphenyl-N-methylcarbamate MTMC:m-Tolyl-N-methylcarbamate MPMC: 3,4-Xylyl-N-methylcarbamate NAC:1-Naphthyl-N-methylcarbamate PHC: 2-Isopropoxyphenyl-N-methylcarbamateXMC: 3,5-Xylyl-N-methylcarbamate Alanycarb:Ethyl(Z)-N-benzyl-N-{[methyl(1-methylthioethyli-deneaminoxycarbonyl)amino]thio}-β-alaninate Ethiofencarb:2-(Ethylthiomethyl)phenyl methylcarbamate Oxamyl: Methyl-N,N′-dimethyl-N-[(methylcarbamoyl)oxy]- 1-thioxamimidate Carbosulfan:2,3-Dihydro-2,2-dimethyl-7-benzo[b]furanyl N-dibutyl-aminothio-N-methylcarbamate Thiodicarb:3,7,9,13-Tetramethyl-5,11-dioxa-2,8,14-trithia-4,7,9,12-tetraazapentadeca-3,12-diene-6,10-dione Pirimicarb:2-Dimethylamino-5,6-dimethylpyrimidin-4-yl dimethylcarbamate Bendiocarb:2,2-Dimethyl-1,3-benzodioxol-4-yl methylcarbamate Benfuracarb: EthylN-[2,3-dihydro-2,2-dimethylbenzofuran-7-yloxycarbonyl(methyl)aminothio]-N-isopropyl-β- alaninate Methomyl:S-methyl-N-[(methylcarbamoyl)oxy]thioacetimidate

The above-mentioned names of insecticidal agents are generic namesdescribed in “Agrochemicals Handbook 1992 Edition” published on Jul. 30,1992 by Japan Plant Protection Association and “SHIBUYA INDEX -1996-(7thEdition)” published on Apr. 1, 1996 by ZENNOH.

In this invention, among the above-mentioned agents, especially2-sec-butylphenyl-N-methyl-carbamate and 1-naphthyl-N-methylcarbamateare preferable due to a high synergistic action with chlorfenapyr.

For the preparation of the insecticidal and miticidal composition of theinvention, it is suitable to formulate as a wettable powder, aqueousconcentrate, emulsion, liquid concentrate, sol (flowable agent), powder,aerosol, or the like, by conventional methods such as admixingchlorfenapyr and publicly known carbamate-type insecticidalingredient(s) with a suitable carrier and auxilliaries, such asemulsifiers, dispersants, stabilizers, suspending agents, penetrants,and the like.

The content of the total active ingredients of the composition of theinvention, expressed as weight/weight %, is preferably in the range ofabout 1-90% for wettable powder, aqueous concentrate, emulsion, liquidconcentrate and sol formulations. The preferable content of total activeingredients is about 0.5-10% for powder formulations and about 0.01-2%for aerosol formulations.

Carriers suitable for use in the insecticidal and miticidal compositionsof the invention may be any solid or liquid carrier which is commonlyused for an agrohorticultural composition. Various surfactants,stabilizers and other auxiliary ingredients may be used according to thenecessity.

In commercially useful formulations, the composition of the inventionmay also be present in a mixture with other active agents, for examplevarious insecticidal, miticidal, fungicidal and herbicidal agents, plantgrowth regulators, repellants, attractants, synergists and fertilizersand fragrances, in order to expand its applicability.

The ratio of chlorfenapyr to the publicly known carbamate-typeinsecticidal ingredient(s) in the insecticidal and miticidal compositionof the invention is about 1 weight part of chlorfenapyr to about0.01-100 weight parts, preferably about 0.5-20 weight parts, of apublicly known carbamate-type insecticidal ingredient(s).

Although the application amount may differ according to prevailingconditions such as the population density, the kinds and cultivationform of the target crop, the weather conditions, the manner ofapplication, and the like, in general, the total amount of chlorfenapyrin combination with the publicly known carbamate-type insecticidalingredient(s) is about 0.1-1,000 g, preferably about 40-500 g, per 10ares. In actual practice, the composition of the invention when in theform of a wettable powder, aqueous concentrate, emulsion, liquidconcentrate, sol, or the like may be diluted with water and applied tothe crop at an application rate of about 100-700 liters per 10 ares.When the inventive composition is formulated as a powder or aerosol, thecrop may be treated with the undiluted formulation.

The insecticidal and miticidal composition of the invention is furtherillustrated in the examples set forth hereinbelow. These examples arenot intended to limit the scope of the invention. The parts all meanweight parts.

EXAMPLE 1

FORMULATION EXAMPLE 1 EMULSION Clorfenapyr  5 parts BPMC 40 parts Xylene25 parts Dimethyl formamide 20 parts Sorpol 3005X 10 parts(Polyoxyethylene type surfactant manufactured by Toho Chemical IndustryLtd., commercial name)

An emulsion is obtained by mixing homogeneously and dissolving theabove-mentioned ingredients.

EXAMPLE 2

FORMULATION EXAMPLE 2 WETTABLE POWDER Chlorfenapyr  5 parts NAC 50 partsCarplex #80 15 parts (White carbon manufactured by Shionogi & Co., Ltd.,commercial name) Zeeklite SP 22 parts (Mixture of kaolinite and cericitemanufac- tured by Zeeklite Ind., commercial name) Calciumligninsulfonate  8 parts

A wettable powder is obtained by homogeneously mixing theabove-mentioned ingredients by jet air mill.

EXAMPLE 3

FORMULATION EXAMPLE 3 SOL (FLOWABLE AGENT) Chlorfenapyr 5 parts NAC 25parts Ethylene glycol 8 parts Sorpol AC3020 5 parts (Toho Chemical Ind.Co., Ltd., commercial name) Xanthan gum 0.1 parts Water 56.9 parts

Chlorfenapyr, NAC and a previously prepared mixture of ethylene glycol,Sorpol AC3020 and xanthan gum are well mixed in water and dispersed.This slurry is then wet pulverized by Dynomill (Shinmaru Enterprises) toobtain a sol (flowable agent).

EXAMPLE 4

FORMULATION EXAMPLE 4 POWDER Chlorfenapyr 0.5 parts BPMC 3.5 parts Whitecarbon 5 parts Clay 91 parts (Nippon Talc Co., Ltd., commercial name)

The above-mentioned ingredients are homogeneously mixed and pulverizedto obtain a powder

Each of the above-prepared formulations is Suitable to be used as anagrochemicaI.

EXAMPLE 5 Test Example 1

In this experiment, the miticidal effect against female imagines(adults) of Kanzawa spider mite (Tetranychus kanzawai kishida) which areresistant to chlorfenapyr is evaluated.

Round leaf disks (2 cm diameter) are cut out of a first leaf of kidneybean by a leaf punch and 4 sheets of the disks are placed on wetsanitary cotton in a plastic cup (8 cm diameter). On each leaf disk, 4female imagines of Kanzawa spider mite (Tetranychus kanzawai kishida)which had acquired a strong resistance to chlorfenapyr are inoculated.

After the inoculation, chlorfenapyr and a carbamate-type insecticidalagent(s) are dispersed in water containing 200 ppm of an extender(Sorpol 3005X manufactured by Toho Chemical Industry Ltd.) and dilutedsuch that a predetermined concentration of active ingredient isobtained. Each plastic cup is sprayed with 3.5 ml of a test solutionwith a rotary spray tower (Mizuho Scientific Co., Ltd.) and stored in aconstant temperature chamber held at 25±1° C. (32 individuals are testedper concentration, 4-5 concentrations are evaluated per formulation and2 performances are repeated). Two days after treatment, the number ofliving and dead female imagines of Kanzawa spider mite (Tetranychuskanzawai kishida) which had acquired a strong resistance to chlorfenapyris counted and the mortality (%) is calculated according to the formulashown hereinbelow.${{Mortality}\quad (\%)} = {\frac{{Number}\quad {of}\quad {dead}\quad {mite}}{{{Number}\quad {of}\quad {living}\quad {mite}} + {{Number}\quad {of}\quad {dead}\quad {mite}}} \times 100}$

Using these data, the LC₅₀ values are obtained by conventional probitanalysis techniques. A co-toxi-city coefficient is calculated byapplying Sun and Johnson's formula (J. Econ. Ent., Vol 53, p. 887, 1960)which is generally used to determine the degree of synergistic activity.

The LC₅₀ value of each individual effective ingredient which constitutesthe insecticidal and miticidal composition of the invention is shown inTable I. The LC₅₀ values and the co-toxicity coefficients of thecomposition of the invention are shown in Table II.Co-toxicity  coefficient = T^(c)$T^{c} = {\frac{{Actual}\quad {toxicity}\quad {index}\quad {of}\quad {mixture}}{{Theoretical}\quad {toxicity}\quad {index}\quad {of}\quad {mixture}} \times 100}$

For T^(c) values greater than 100, the greater value indicates astronger synergistic action. For a T^(c) value equal to 100, an additiveaction is indicated. For T^(c) values less than 100, the lesser valueindicates a greater antagonistic action. A more detailed description ofthe calculation or the co-toxicity coefficient using theabove-referenced Sun and Johnson formula follows.

The LC₅₀ values of Test Compound A alone and Test Compound B alone andthe LC₅₀ value of the (A+B) mixture M are determined.

Actual Toxicity Index of Mixture M=M^(ti)

Each LC₅₀ value of effective ingredient A and effective ingredient B andthe LC₅₀ value of the mixture of A+B are used to determine the actualtoxicity index as shown in the equation below.$M^{ti} = {\frac{{LC}_{50}\quad {of}\quad A}{{LC}_{50}\quad {of}\quad M} \times 100}$

Theoretical Toxicity Index of Mixture M=Th.M^(ti) $\begin{matrix}{{{Th}.M^{ti}} = \quad {{{Toxicity}\quad {index}\quad {of}\quad A \times \% \quad A\quad {in}\quad M} +}} \\{\quad {{Toxicity}\quad {index}\quad {of}\quad B \times \% \quad B\quad {in}\quad M}}\end{matrix}$

Toxicity Index of B=B^(ti)$B^{ti} = {\frac{{LC}_{50}\quad {of}\quad A}{{LC}_{50}\quad {of}\quad B} \times 100}$

Toxicity Index of A=A^(ti)

A^(ti)=100

TABLE I Evaluation Of The Effect Of Test Compounds Against Female ImagoOf Kanzawa Spider Mite Which Have Acquired Resistance AgainstChlorfenapyr TEST COMPOUND LC₅₀ (ppm) Chlorfenapyr 1500 BPMC 3200 NAC2700 Ethiofencarb 2100

The tested mite was a female imago of the chlorfenapyr-resistant strainof Kanzawa spider mite which was obtained by a long artificial selectionprocedure against chlorfenapyr in a laboratory on a colony of Kanzawaspider mite which had been collected in the field. As the LC₅₀ value forchlorfenapyr against a susceptible strain of spider mite is about 5 ppm,this strain has developed about a 300-fold resistance to chlorfonapyr.

It is generally known that the effect of carbamate-type insecticidalagents against spider mites is weak, and all the tested carbamate-typeinsecticidal agents showed only low miticidal effects.

TABLE II Evaluation Of The Effect Of Test Mixtures Against Female ImagoOf Kanzawa Spider Mite Which Have Acquired Resistance AgainstChlorfenapyr RATIO (Chlorfenapyr: LC₅₀ TEST MIXTURE carbamate) (ppm)T^(C) Chlorfenapyr + BPMC 1:10 310 940 Chlorfenapyr + NAC 1:10 480 520Chlorfenapyr + Ethiofencarb 1:10 440 460

As can be seen from the data on Table II, the co-toxicity coefficient ofthe test mixtures is a value greater than 100, which is indicative ofstrong synergistic action between chlorphenapyr and BPMG, NAC orEthiofencarb. Though the detailed mechanism of the synergistic action ofthe composition of the invention is not clear, it is estimated that themetabolic system (group of enzymes), with which the spider mites, whichhas developed resistance to chlorfenapyr, detoxifies and decomposes thecompound, be inhibited by a carbamate-type insecticidal ingredient(s) todemonstrate such an action. Therefore, a second ingredient of theinsecticial and miticidal composition is thought not to be limited tothe carbamate-type insecticidal agents tested in the above-mentionedexamples and the carbamate-type insecticidal agents concretely mentionedabove.

What is claimed is:
 1. An insecticidal and miticidal composition whichcontains as active ingredients (a) chlorfenapyr; and (b) a synergisticamount of at least one of a substituted phenylmethylcarbamateinsecticidal compound.
 2. The composition of claim 1 wherein thesubstituted phenylmethylcarbamate insecticidal compound is selected fromthe group consisting of fenobucarb, ethiofencarb, isoprocarb, metolcarb,xylylcarb, propoxur, carbaryl, 3,5-xylylmethycarbamate, and beniocarb.3. The composition of claim 2 wherein the substitutedphenylmethylcarbamate insecticidal compound is fenobucarb, ethiocarb orcarbaryl.
 4. The composition of claim 3 wherein the substitutedphenylmethylcarbamate insecticidal compound is fenobucarb.
 5. Thecomposition of claim 1 wherein the chlorfenapyr is present in a ratio ofabout 1 weight part to about 0.01-100 weight parts of the substitutedphenylmethylcarbamate, insecticidal compound(s).
 6. The composition ofclaim 4 wherein the ratio is about 1 weight part of chlorfenapyr toabout 0.5-20 weight parts of the substituted phenylmethylcarbamatecompound(s).
 7. A process for the preparation of a composition of claim1 which comprises admixing the active ingredients with aagrohorticulturally acceptable solid or liquid carrier.
 8. The processof claim 6 wherein the active ingredients comprise chlorfenapyr incombination with an insecticidally synergistic amount of fenobucarb,ethiocarb or carbaryl.
 9. The process of claim 7 wherein thechlorfenapyr is present in a ratio of about 1 weight part to about0.5-20 weight parts of at least one of fenobucarb, ethiocarb orcarbaryl.
 10. A method of controlling insecticidal or miticidal pestswhich have acquired resistance to4-bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)pyrrole-3-carbonitrileat a locus which comprises applying to the locus an effective amount ofan insecticidal and miticidal composition comprising as activeingredients synergistic amounts of4-bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)pyrrole-3-carbonitrileand at least one insecticidal substituted phenylmethylcarbamate.
 11. Themethod of claim 10 wherein insecticidal compound is selected from thegroup consisting of fenobucarb, ethiofencarb, isoprocarb, metolcarb,xylylcarb, propoxur, carbaryl, 3,5-xylyl methylcarbamate, andbendiocarb.
 12. The method of claim 11 wherein the substitutedphenylmethylcarbamate insecticidal compound is fenobucarb, ethiocarb orcarbaryl.